Fastener driving machine



June 2, 1942. F POLZER FASTENER DRI-VING MACHINE Fild Feb. 10, 1942 INVENTOR ATTORNEYS Patented June 2, 1942 v 2,285,354 FASTENER. DRIVING MACHINE Fridolin Pelzer, Norwalk, Conn., assignor to The E. H. Hotchkiss Company, Norwalk, Conn., a corporation of Connecticut applicati@ February 1 0, 1942, serial No. 430,227

8 Claims.

This invention relates to a fastener driving machine of the type in which a spring` is used for driving the plunger to set the fastener, and has for an object to provide aconstruction in which if it is desired to change the driving power, as for example to increase or decrease the driving power, the spring may be easily and quickly changed with a simple operation, to provide Cil either a heavier or a lighter spring as desired. -f

It is also an object to provide such a construction in which the means for retaining the spring in the housing is releasable by movement against the action of the spring and in which a manually releasable means'is provided normally molding said spring retaining means against movement to the released position to prevent accidental or undesired release of the spring during handling or use of the device.

Fig. 3 is a partial front elevation and partial section.

The staple driving machine shown is of a construction disclosed in my prior application for patent for fastener driving machine Serial No. 371,011, filed December 20, 1940, and comprises a housing 5 the side walls of which are shaped at 6 to provide an upright guideway 1 for the support or plunger 8 for carrying thefastener driver 9. This support or plunger has. a substantially rectangular head portion I0 and a stem II providing a shoulder I2. The head portion is recessed on its lower front face as indicated at I3 to receive the upper end of the driver 9, and in the wall of this recess is anotherrecess I4 to receive the lug I5 cut and bent backwardly from the driver to connect the driver to the plunger so that the driver will be carried upwardly `with the upward movement of the plunger. The shoulder I6 at the top of the recess I3 engages the upper end of the driver so as to force the driver downwardly to drive the fastener as the plunger is driven downwardly under action of the spring l1. This spring embraces `are released from the hooks.

the stem II and rests at its lower end on the shoulder I2. At this upper end it engages the under side of the top wall I8 of a yoke I9.

This yoke maybe stamped and formed from sheet metal, and in the construction shown comprises two inverted U-shaped members, the inner member having the top wall I8 connecting two downwardly extending arms 20 embracing the side walls of the housing and the second member including a top wall ZI connecting short side walls or arms 22 embracing the top portion of the front guideway portion of the housing and fastened to the Wall I8 `by any suitable means, such for example as spot welding. The side arms 29 and 22 therefore embrace the four sides of the upper portion of the guideway and retain and center the yoke thereon. On the outer sides of the plunger guide portion 6 of the housing are downwardly extending lugs 23 forming hooks opening downwardly,`and these lugs may be cut from the wall 6 and bent outwardly as indicated in Fig. 3. Each arm 20 of the yoke is provided with an opening 24 adapted to slide over these hooks so that the lower edge 25 of the opening can engage under the hook, as shown in Figs. 2 and 3, to retain the yoke in position on the body. It will be seen the pressure of the spring I'I tends to force the yoke upwardly `and hold these lower edges of the openings 24 under the hooks.` The openings 24 are suiiiciently large in a vertical direction so that the lugs 23 may readily pass through the openings in applying or releasing the yoke.

The yoke may be readily removed by forcing it downwardly against the action of the spring l1, which can be done by pressure of the hand on top of the yoke until the walls of therarm under the hooks 23 are released therefrom permitting the arms to spring outwardly, as indicated in dotted lines, Fig. 3. The arms are of sufliciently resilient material and are set so that they will automatically spring outas soon as they After the arms are thus released the yoke may be readily lifted from the body permitting removal of the springl I1 and if desired the plunger andpthe fastener driver. Therefore if it is desired to change the driving force on the driver all that is necessary is to insert a new spring of the desired tension, either lighter or heavier, and then again apply the yoke forcing it downwardly until the arms 20 can be pressed inwardly to `engage under the hooks 23'. The top wall I8 of the yoke not only forms an abutment for the spring I'I buthas an opening therein through which the upper end of the stem Il projects and by which it is guided and centered in the housing guideway.

To prevent accidental release of the yoke and the spring, such for example as by inadvertent pressure on the top of the yoke to thus force it downwardly and permit the side arms 2E) to be released from the hooks 23, especially where the spring I7 may be a relatively light spring, manually releasable means is provided to prevent this accidental or undesired downward movement of the yoke by pressure on the top thereof. This means, however, is constructed so that it may be readily released to permit forcing the yoke downwardly to release it when it is Idesired to change the spring or remove the plunger or driver. This retaining means may take various forms, but in the construction shown it comprises a fiat spring 26 secured and pivoted to one arm 20 by a rivet 21. Adjacent its upper end it carries an inwardly extending stop lug or pin 28 which may pass through an opening in the arm V20 and extend over the top edge 29 of one of the side walls 6 of the housing. It will be seen that as this member 28 extends over the top of the wall 6 or some other stop shoulder on the housing, it will prevent downward movement of the yoke until this stop 28 Vis withdrawn from the stop or holding position, such for example as shown in dotted lines, Figs. 2 and '3. By engaging the finger under the top end 30 of the spring 26, this end may be drawn outwardly to release the catch 28 after which the yoke may be forced downwardly by pressure on its top wall to permit release of the arms 20 from the hooks 23 and permit removal of the yoke and the springs and plunger, etc., as above described. The rivet 2l may also rform a pivot topermit the spring 26 to be swunglaterally to oneside, as shown in dotted linesQFig. 2, if it is desired to 'have the catch retained in released position. It is'preferred that the stop member 28 may pass through an opening in the side wall of the yoke or .be located directly under the top wall I8 of the housing, as

indicated in' Fig. 3, so that'it is supported and backed up by this opening or the top wall and will not be forced outof position by pressure of the Ystop shoulder`29 against this member.

At the lower end of each of the arms '2D is an inwardly. extending lug 3l each passing through an opening 32 in the outer side wall 5 of the ,guideway These extend into the guideway for the plunger over the top of a resilient cushioning bumper 33 under the plunger vto arrest downward movement of the plunger and cushion the blow. This bumper may be of various construcv.

tions but that shown comprises a central rubber plug 34 embraced by a heavy spring 35. This bumper is supported `on a transverse wall 35 mounted'in the lower `part of the guideway. In the present construction this wall is a block`having lugs 31 extending into and seated in openings 38 in the walls 6 whereby the block 36 is supported. It has a notch in its forward edge for passage of the driver 9. The'lugs v3l by extending inwardly over the bumper prevent the bumper from moving upwardly in the plunger guideway so that itis retained in proper position on the wall 36. The head I0 of the plunger is provided with lgrooves 39 to formv clearance for the lugs 3| and permit the plunger to move downwardly past these lugs.

The device is illustrated as adapted for driving substantially U-.shaped or two-pronged staples or staple fasteners 40, but the mechanism may be employed for driving other types of fasteners, such for example as other types of staples, tacks and nails, it being necessary merely to change the shape or form and size of the fastener support and guiding means and the driver for the fastener to correspond with the type and size of fastener used. Also the device is shown for driving a staple fastener directly into the article to be fastened without clinching and is therefore what is known as a tacker, but it may be used with a base carrying an anvil `in alignment with the staple driver for` bending over and clinching the staple prongs, as in the type of machine known as a stapler, such base and anvil not being shown, however, in the drawing, as they may be of a conventional type.

Mounted in the housing at the lc-wer part thereof is a staple support and guide di. This may be a solid bar but is preferably formed of sheet metal and substantially U-shaped in cross section, as clearly shown in theprior applicaytion above noted. The staples 40 preferably in -a connected strip are supported with their cross 'bars' 42 on the Atop of this supportwith the Aleg portions at the sides of the support and are guided'thereby to the staple ldri-ving position under the driver V9, the staple strip being inserted on the support at the right hand yor rear end of the housing. The staples are fed along the sup- Yport by means of a follower 43 of substantially inverted Uk-shape to slide along the top of the support 21 with its side walls embracing the support. jAt its forward end the follower Amay have a downwardly extending lip 44 to engage the rear ofthe upright guide :wall 45 forming the rear wall ofthe staple guidewayA vto insure that the forward end of the f ollower'is not fed into `the position under the driver 9. The follower is provided with a loop '4B embracing and slidable on a rod 47 locatedbetween lthe sides of 4the support 4i and on which isa coil spring 48 tending to shift Athe follower forwardly along the sup- Vport 4| to feed the fasteners forwardly to the driving position. The end of the rod may be flattened as shown at '4'9to make it wider to prevent the loop 46 vfrom sliding off the end of the rod.

The wall 45 is mounted at the 'forward end of the guide '4| between the side walls'thereof `and is an L-shaped member. The lower'leg 50 rests on the bottom wall 5l Yof the', guide and is secured thereto by any suitable means such as the rivets 52, welding or the like. 'The front Wall of the raceway for the driver 9 and for guiding the staples is formed 'by a removable plate '53. This plate .is mounted vto slide vertically on guide flanges (not shown) o n the side walls of the housing so that the plate may be `drawn downwardly and removed, it being 'held in position by a catch lug 54 on jthe spring catch'55.

By liftingthe lower Afree end of catch 55the plate ,53 Will be released and'may be` withdrawn downwardly to give access to thefront endof the staple supportand the vlower portion of the driver 9 and also to .permit removal of any staple which may become jammed in the raceway.

The means for lifting the plunger against the action of the spring `I1 to compress this spring and also to raise the driver 9 to permit a fastener to be fed into the raceway under this driver .in position tobe driven thereby, is mounted and assembled as a separate unit mountable in and removable as such from the housing, as clearly shown and described vin the prior application ,above noted. It is not shown in detail here as it is not claimed specifically. The end portion of lthe housing 56 of this unit is shown by dotted lines Fig. 2 in partially removed position. Pivoted between the sides of this inner housing is an operating rhand lever the forward end of which is shown at 51 pivoted at 58 and carrying a roller 59 running on the cam edge 60 of a cam lever 6I pivoted in the housing at 62. This lever extends I wardly. The cam lever 6l carries a pawl 66 pivoted to the lever at 61 and adapted to seat at its upper forward edge under the shoulder 68 on the plunger l; The upper end of this pawl is held against the plunger by aspring 69. When the lever 51 is depressed the roller 59 runs along the cam edge 69 raising the lever 6l, pawl B and with it the plunger 8, thus raising the driver 9 and compressing the spring I1. As it approaches its upper position the cam 19 on the pawl engages the cross pin 1| and by camming action thereon withdraws the upper end of the 'pawl G6 from the shoulder 678, releasing the plunger and permitting it to be forced downwardly by the spring I1 to force a staple downwardly through the raceway between the walls 45 and 53, which staple has been fed into a position in this raceway and under the driver when the driver reached its uppermost position.

It will be seen from the above that the lock or catch 28 prevents accidental shifting of the y yoke I9 downwardly to permit the lower ends of the arms 29 to disengage from the hooks 23 durf ing normal operation and handling of the device. Should it, however, be desirable to change the spring all that is necessary is to release theA catch 23 which will release the yoke and permit it to be forced downwardly to release the arms 2i] from the hooks 23 and permit withdrawal of the yoke from the housing, after which the spring l1 may be removed and a new spring inserted in its place. Then the yoke can be replaced so that it forms a guide for the stem Il and an upper abutment for the spring.Y

Having thus set forth the nature of my invention, what I claim is:

l. A fastener driving machine comprising a housing having an upright guideway open at the top, a driver and its support mounted in the guideway for reciprocating movement, a spring for moving the driver downwardly for driving a fastener, a removable yoke having a wall over the open top of the guideway and forming an abutment for said spring, means for detachably connecting said yoke to the housing comprising downwardly directed hooks on the housing and cooperating means on the yoke engaging under the hooks, said spring acting to force the yoke upwardly to retain said cooperating means in the hooks so that the yoke must be forced downwardly against the action of the spring to release the yoke, releasable stop means on the yoke to engagea shoulder on the housing to prevent said downward movement of the yoke, operating means for raising the driver against action of said spring preparatory to driving a fastener, and means for feeding fasteners to the driving position under the driver.

2. `A fastener driving' machine comprising a housing having an upright guideway open at the top, a driver and its support mounted in the guideway for reciprocating movement, a spring for moving the driverdownwardly for driving a fastener, a removable yoke having a wall over the open top of the guideway and forming an abutment for said spring, cooperating means on the housing and yoke for detachably connecting the yoke lto the housing and releasable by downward movement of the yoke against the action `of the spring, manually releasable cooperating means on the yoke and housing to hold the yoke against said downward movement, operating means for raising the driver against action of said spring preparatory to driving a fastener, and means for feeding fasteners to the driving position under the driver.

3. A fastener dri-ving machine comprising a housing having an upright guideway open at the top, a driver and its support mounted in the guideway for reciprocating movement, a spring for moving the driver downwardly for driving a fastener, a removable yoke having a wall over the open top of the guideway-and forming an abutment for said spring, cooperating means on the housing and yoke for detachably connecting the yoke to the housing and releasable by downward movement of the yoke `against the action of the spring, manually releasable cooperating means on the yoke and housing to hold the yoke against said downward movement comprising a spring secured to the yoke and having astop normally held by said spring in position to engage a shoulder on the housing, operating means for raising the driver against the action of the spring preparatory to driving a fastener, and means for feeding fasteners to the driving position under the driver.

4. A fastener driving machine comprising a housing having an upright guideway open at the top, a driver and its support mounted in the guideway for reciprocating movement, said support having a stem, a spring for moving the driver downwardly for driving a fastener embracing the stem and removable through the top of the guideway, a removable yoke having a wall over said open top of the guideway forming a guide for said stem and an abutment for the spring, means for detachably securing the yoke to the housing and releasable by downward movement of the yoke against action of the spring, manually releasable cooperating means on the yoke and housing to prevent such downward movement, operating means for raising the driver against action of the spring, and means for feeding fasteners to driving position under the driver.

5. A fastener driving machine comprising a housing having an upright guideway open at the top, a driver and its support mounted in the guideway for reciprocating movement, a spring Y for moving the driver downwardly for driving a fastener and removable through the top of the guideway, a removable yoke having -a wall over the open top of the guideway and forming an abutment for said spring, said yoke having downwardly extending -arms embracing opposite sides of the guideway, downwardly opening hooks on Vthe outer walls of the guideway, said arms havfastener and removable through the top of theV guideway, a removable yoke having a wall over the' open top of the guideway and forming an abutment for said spring, said yoke having downwardly extending arms embracing vopposite sides of the guideway, downwardly opening hooks on the outer Walls of the guideway, said arms having openings to receive the hooks and retain the yoke on the housing, said spring tending to raise the yoke and 'retain said openings on the hooks, ,and a flat spring mounted on an arm of the yoke and carrying a stop extending through an opening in said arm to engage the housing to prevent downward movement of the yoke to release the arms, and said stop being releasable against the action of the latter spring.

7. A fastener driving machine comprising a housing having an upright guideway open at the top, a driver and its support mounted in the guideway for reciprocating movement, a spring for moving the driver downwardly for driving a fastener and removable through the top of the guideway, a removable yoke having a wall over the open top 'of the guideway and forming an abutment for said spring, said yoke having downwardly exten-ding arms embracing the opposite sides of the guideway, means for detachably securing said arms to the housing releasable by downward movement of the yoke Iand normally held in the upper position by action of the spring, `a supporting wall at the lower part of the guideway, a resilient bumper supported on said wall to receive the blow of the support and limit its downward movement, lugs on the arms extending inwardly over the bumper to limit upward movement of the bumper, and manually releasable means normally holding the yoke against downward movement to release the arms.

8. A fastener driving machine comprising a housing having an upright guideway open at the top, a driver and its support mounted in the guideway for reciprocating movement, said support having a stem, a spring for moving the driver downwardly for driving a fastener embracing the stem and removable through the top of the guideway,V a removable yoke having a wall over said open top of the guideway forming an abutment for the spring and having an opening forming a guide for said stem, said yoke having downwardly extending arms embracing opposite sides of theguideway, downwardly opening hooks on the outer walls of the guideway, said arms having openings to receive the hooks and retain the yoke on the housing, said yoke being movable downwardly to release the arms from the hooks and normally held in its upper position by the spring, and manually releasable means for retaining the yoke in its upper position and preventing downward movement to release the arms.

FRIDOLIN POLZER. 

